Pick for mining shearing-machines.



. tical cuts inthe solid coal toa Y to be of little value.

UNITED STATES ATEiv OFFICE, g

' RIPLEY c. HOFFMAN, or osKAL'oosA, Iowa.

mcx ro'n. Mime measure-mamas.

speeiacaeien of Letters Patent.

Patented Dec. 25:, 1908.

Application fled Apr-n 9, 1907. Serial No. 367,169.

'in s, which form a part of this spec cation.

y invention relates in general to mining machineryand more particularlyto an improved pick for shearing machines.

In coal mining it is customaii'iy to make verord spaces for thedisplacement of the coal when blasted It is usual to employ shearingmachines "in making these cuts comprising a series of icks arranged in acircle and supported in a older at the end of an extension bar. Thebaris reciprocated' and rotated so that the picks chip away the coal,thereby forming a cut of a width equal to the diameterof the plane ofrotation of the picks. The icks ave heretofore been supported in the hodots with their cutting edges extending radially with res ect to thecircle in which they are arrange which results in the coal removed inmaking the out being so finely divided as The picks as now arranged inthe holders. frequently become so filled with pieces of coal as tointerfere with the operation of cutting.

- The primary object of my invention is to J provide an'improved ick formining shearing greater commercial value.

- older an in a circle, the cutting edges of the several I machineswhich will e so shaped as to cut efliciently at all times without cloged with ie'ces of coal.

further 0 ject of my invention is to pro becoming vide a tool for miningshearing machines, the

picks of which will be'so' arranged that the coal -dislodgedin making acut will not be. divided into fine particles, but will be of pea and'nut sizes and therefore of The embodiment of my invention hereindisclosed may be generally described as comprising a dplurality of pickssupported in a arranged with their cutting edges picks being bifurcatedand spaced agprt so as to form assage-wa s to permit the 'slodged pieces0 coal to fa through.

- My invention willbe more fully described hereinafter with reference tothe accompanying drawing in which the same is illustrated as embodied ina convenient and practical form and in which Figure 1 is a centralsectional view on line 1-1-1 Fig. 2; Fig. 2 an end elevation lookingfrom-the left in Fig. 1; and Fig. 3 a side elevation of one of the picksremoved from the holder.

The same reference characters are used to designate the same parts inthe several figures of the drawings.

Reference character A indicates the end of an extension bar of a miningshearing machine upon which is supported a pick holder B. The end of theextension bar is angular in cross-section and preferably tapered so asto fit tightly within a socket of corresponding cross-section in the endof the holder. The opposite end of the holder from the extension bar isprovided with an outwardly flaring circular socket B in which arereceived the shanks of the picks C.

Each of the picks C is ting edge ofi-set outwar rovided with a cutwithrespect to its shank, the cutting edge eing notched at c v to providetwo cutting portions 0 and C The inner surface of the plck is providedwith a channel 0 extending inwardly from the notch in the cutting edge.The sides of the pick are cut away as shown at 0 so that when aplurality of the picks'are secured within the holder channels are formedbetween the adjacent picks, as clearly shown in Figs. 1 and 2..

The shank C of each pick *has the crosssection of a sector so that whenthe proper number of picks, as for instance five, are secured to theholder the shanks C" will lie close together and be tightly wedgedwithin the socket B of the, holder. In order to retain the shanks of thepicks in proper relative positions one surface is provide w1th a recessc and the other surface with a projection c, a recess in the shank ofone pick receiving the projection on the shank of e adjacent pick. Inorder to remove the picks an opening 6 rovided through the ho ey may beinserted to force outwardly the shank of one of the picks after whichthe other picks may beeasily removed.

From the foregoing description it. will be' der through which Q a i v907,360

picks. It will also be observed that the the inner surface extendinginwardly from pieces of dislodged coal will not become the cutting edge,the longitudinal outer surwedged between the picks as the passagefacesextending from the cutting edge being 15 ways between adjacent pickspermit the cut away to form grooves between the pick 5 pieces of coal tofall. and adjacent picks when a plurality of picks Having nowfullydescribed my invention, are assembled in the holder; what I claim as newand desire to secure by 1 In testimony whereof, I sign this specifica-Letters Patent is: tion in the presence of two witnesses.

A pick, for use in mining shearing machines RIPLEY C. HOFFMAN. 0comprising a shank adapted to be secured in Witnesses:

a holder, a divided cutting edge off-set out- W. O. BURRELL,

wardly from the shank, a central channel in H. W. GLEASON.

